Naomi Campbell drew the big guns out for her “Fashion for Relief” runway show last night in Bryant Park to help raise money for earthquake-ravaged Haiti. Chris Brown, Kelly Osbourne, Donna Karan and Helena Christensen all walked the catwalk for the charity event, which will raise funds for CARE.

The show, styled by Rachel Zoe andhosted by Campbell and Duchess of York Sarah Ferguson, follows Campbell’s first “Fashion for Relief” event in 2005, which raised $1 million for Katrina victims.

But there was no sign of Campbell until the last minute. A spy said, “Naomi didn’t show for her interviews earlier in the day, and she got ready at another venue away from the tents, but she made it there just in time.”

Meanwhile, “Sarah Ferguson requested more privacy in the backstage area to get changed for the show. She was shocked to see that she’d have to change in front of camera crews, models and men. So she changed in a private room.

“Chris Brown, who wore a Dolce & Gabbana suit, said it was his first time working with Rachel Zoe and he was excited to meet her,” our source said. “He even asked if there was room for him in her reality show. And Harvey Weinstein was seen following wife Georgina Chapman as she ran towards makeup.”

Ackerman, who wore a Michael Kors pink dress for the show, told us she immediately accepted Campbell’s call to take part, saying, “Not only is it exciting that Naomi Campbell is on the phone, it’s exciting to participate because it’s for a good cause.”

The looks and accessories — including a custom Louis Vuitton handbag created by Marc Jacobs — will be up for auction on Net-a-porter.com starting March 15.